There has long existed a need for effective closure devices that are suitable for use as doors, hatches, manways, access ports or covers, especially where the intended use may subject the closure to high pressures or vacuums. Such closures are employed, for example, in autoclaves, pressure vessels, chemical reactors, pulp extractors, submarine hatches, bank vaults and space vehicles or simulators. There has also existed a need for effective closure means that are suitable for use in coupling opposed abutting surfaces such as might be found with flanged pipe sections, wheels and mounting hubs and the like.
In the past, closure devices suitable for use in these and other related applications have sometimes utilized a plurality of evenly spaced lug bolts around the perimeter of the closure to provide tight sealing engagement. However, such closures suffer from the disadvantage that considerable time and effort are required to tighten and loosen each bolt each time that the closure is engaged or disengaged. Moreover, where there are a plurality of bolts or nuts that must be individually tightened when engaging a closure, care must be taken to gradually tighten those in alternate positions around the perimeter of the closure so that the forces are evenly distributed against the gasket or other surfaces that are being brought into abutting relationship with each other. Where the individual locking bolts are not tightened in an appropriate manner, hazardous leakage or other failure of the closure may result. Also, because of the numerous individual parts that are required to effect the closure, some parts are likely to become lost or misplaced when using such conventional apparatus.
In order to reduce the time and effort required to effect such closures, bayonet type locking devices have been developed for use in some applications. With a bayonet type closure, the surfaces or objects to be coupled are provided with locking lugs that are stabbed together and then rotated relative to each other to provide locking engagement. Bayonet closures have been widely used, for example, as locking mechanisms for camera lenses. However, for larger objects or objects having considerable mass, bayonet type closures are undesirable because of the force that must be applied to rotate one object relative to the other. Moreover, in some applications it is undesirable or impossible to rotate the objects that are to be coupled relative to each other.
Many other types and configurations of closure devices have also been disclosed in the prior art. Such devices are disclosed, for example, in U.S. Pat. Nos. 1,233,171; 1,484,216; 2,283,974; 2,553,220; 2,862,728; 3,923,407; 4,183,189; and 4,320,911.
U.S. Pat. No. 1,233,171 discloses an apparatus for coupling flanges wherein beveled or wedge-shaped lug members from one flange are inserted through slots in the opposing flange. Threaded bolts are utilized to force the beveled surface of the lug against the bearing surface of the slotted flange, thereby bringing the opposing flanges into closer contact with each other. The use of packing as a sealing means between opposing flanges is also disclosed.
U.S. Pat. No. 1,484,216 discloses a flanged pipe or hose connection wherein clamping jaws are caused to bring opposing flanges into contacting relation by tightening an external clamping ring or nut that threadedly engages the periphery of one of the flanges.
U.S. Pat. No. 2,283,974 discloses a coupling for flange members wherein opposing wedge-shaped surfaces are driven into frictional engagement by a tangentially applied force that is directed through the head of a threaded bolt.
U.S. Pat. No. 2,553,220 discloses a detachable coupling means for use in mounting aircraft engine accessories. The apparatus disclosed therein utilizes a ring-like element disposed in an annular groove for increasing frictional engagement between circumferentially spaced, axially projecting, wedge-like teeth. In different embodiments, the ring-like element is either expanded or contracted by a threaded bolt or similar apparatus.
U.S. Pat. No. 2,862,728 discloses a connector for coupling a waveguide section. The disclosed apparatus utilizes a series of pivoted dogs arranged to be carried by a choke at the end of the waveguide section, and a rotatable collar operable to clamp the dogs against the back of the flange on the mating waveguide section to force the flange and the choke tightly together.
U.S. Pat. No. 3,923,407 discloses a mechanism for connecting and disconnecting crane sections. A motor-driven pinion engages with teeth on the outer periphery of a bearing race to rotate the crane. The locking mechanism comprises a ring which is received in the external groove of an annular ring member housing secured to the upper crane section. A power actuator extends between the ends of the locking ring member and can selectively expand or contract the ring. U.S. Pat. No. 4,183,189 discloses a flange connector which utilizes remotely controlled hydraulically actuated drive motors connected to a ring gear for simultaneous actuation of clamp dogs spaced about the circumference of the flange.
U.S. Pat. No. 4,320,911 discloses a penetration apparatus with a bayonet plug in a ramp-activated lock for use in spacecraft.
Notwithstanding the foregoing devices, however, there remains a need for a simple and effective closure device that is adapted to provide excellent and evenly distributed sealing engagement, and which can be quickly engaged or released with relatively little effort. A closure device is also needed that can achieve these desirable results without requiring rotation of either of the parts to be coupled.